Currently used packs, commonly called “blister packs”, or similar containers, such as bottles, small boxes, and so on, are filled in a filling station, where at least one article is introduced into each blister or a series of articles are filled to each bottle or each box.
In the following, reference will be more often made only to the blister-packaging method. However, it should be understood that the invention, as well as all considerations made herein below, apply mostly also to packaging articles into bottles or boxes or other similar containers, as long as the feeding method and apparatus used are the same or very similar.
The known apparatuses for filling the blisters, according to different techniques, are particularly efficient and reliable for high quality articles, such as pharmaceutical or pharmaceutical-like products, that is for articles, whose dimensions are very homogeneous.
However, feeding articles having substantially different dimension, can be particularly difficult.
Typically, the blister filling apparatuses known to those skilled in the art, and often similar devices for filling bottles and boxes as well, include a plurality of feeding channels, along which the articles are taken in rows to the blisters, for instance made in a band, or to the bottles or boxes.
The lower ends of the channels touch the band surface and the articles are fed into the respective blisters, as they pass therebelow.
The channels are connected in parallel with a feeding device, e.g. a vibrating hopper, inside which the articles are contained in bulk.
The hopper vibrations, of prefixed amplitude and frequency, facilitate a systematic introduction of the articles into each channel.
As already mentioned, in case of high quality articles, which all match perfectly the required size, all articles pass freely through the channels and enter the blisters each time underlying, without creating jams inside the channels and allowing a substantially continuous and regular flow therein.
In case of lower quality articles, e.g. for alimentary use (chewing gum, candies, etc.), the hopper can contain articles which do not match perfectly the nominal size and can provoke jams and obstacles in the channels, usually in their inlet area. This fact negatively affects the flow of articles being fed to the containers.
The jams and obstacles can be caused by articles, whose dimensions are not compatible with the channels sections, or by articles sticking together, which thus form groups.
Typically, the articles placed in bulk in the hopper after a selection or they are selected as they are fed to the containers. However, generally only one hopper is provided and the selection causes a temporary interruption of the flow of articles. The article flow interruption may provoke either missing articles in the containers or delay in the package operation. Sometimes, it can even require the machine to be stopped, all this resulting in considerable downtime.